Detailed Explanation for this Vulnerability Test
The remote host is affected by the vulnerability described in GLSA-200406-21
(mit-krb5: Multiple buffer overflows in krb5_aname_to_localname)

The library function krb5_aname_to_localname() contains multiple buffer
overflows. This is only exploitable if explicit mapping or rules-based
mapping is enabled. These are not enabled as default.
With explicit mapping enabled, a possible hacker must authenticate using a
principal name listed in the explicit mapping list.
With rules-based mapping enabled, a possible hacker must first be able to create
arbitrary principal names either in the local realm Kerberos realm or in a
remote realm from which the local realm's service are reachable by
cross-realm authentication.

Impact

A possible hacker could use these vulnerabilities to execute arbitrary code with
the permissions of the user running mit-krb5, which could be the root user.

Workaround

There is no known workaround at this time. All users are encouraged to
upgrade to the latest available version.